From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.4 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id E07791F404 for ; Wed, 7 Feb 2018 01:13:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754260AbeBGBNY (ORCPT ); Tue, 6 Feb 2018 20:13:24 -0500 Received: from mail-oi0-f74.google.com ([209.85.218.74]:44190 "EHLO mail-oi0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754223AbeBGBNW (ORCPT ); Tue, 6 Feb 2018 20:13:22 -0500 Received: by mail-oi0-f74.google.com with SMTP id w135so1851725oie.11 for ; Tue, 06 Feb 2018 17:13:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:date:in-reply-to:message-id:references:subject:from:to :cc; bh=LbJMlIMyc6KlQKERjWKxRE4r4P4rOxFjjeHAPZ88US4=; b=opZk3ES3Rz1ntBK9ufdio64rY8F6/TfHVRWbPbMY21vnuCBTXWCISzQoY3zx9PqkWX +Y5UNl1g/wJLLdse9cEKB6//QaQ5WhyyR4OceWx7rPCo9VQUKehK2rEu/vaRBg8U9ZdW xCutiWY3pi5b8+K/SXcllnjbLw9A+uBimbcPNgHrdXT7mz1ZlBHMf3UxULmB79XRPiCZ hlmuindMjvSilBY667dN+/7GqvJBc8vyJzZDqOO440fZ6mUVEJz54mXd114LZTpedB96 72FGJsXgrsvkWCsT52O427q75y3TGqONHkjwACciiTLuPGaM90mT+1Ut9vP0579npqDi /JOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id :references:subject:from:to:cc; bh=LbJMlIMyc6KlQKERjWKxRE4r4P4rOxFjjeHAPZ88US4=; b=t+h4NOaPfqkiLUDg2R58faRD0qREWJqd1IZX93vkQcGI17W5/zc/f9fPAKWE1EfJRQ alx0Ro0024dPhfTX4ACl2cV0u6VR30gjbpPCNJE6PmM/BLbshPZdqXIieoKe2Wp1DKHe cqubpApFDqu2oBwAGJXb81GhdjVmhl7+LgtdqA8SVnksjy2tGNfo++EtviIFTu6SdYKL gF3LaT05HrHtoE1MUa7YhbRJvFR9pim408AUmdVrTyM2TV+tbYwt3Ory8dUhPE0OzV0O qM0Y6XwIloqfQ293znkHPYbh6fJj8HkYuXgAqW4kCudMMB8bo74OB3vLLRDl1WroXiGW iyIg== X-Gm-Message-State: APf1xPDq1VR/OONrwL9iILJjXkExKFwkjSRxlGMfhUgEX7z6MnHO964Y okbF6KjLWxjp6deCTOcUovS5v5QjvcjuoOU5GsEAN7lEfncjKMc2RmUXv6ms1XHSp16ERUTohEF 4bGoi0MS8nOQ0b0SAlJJF9R80KFOH+xqbeAObWwJ06q0aN0kBgINbDcqmGw== X-Google-Smtp-Source: AH8x226Zsv1TZZdFT8LyhOyiws7AWoKD2B2wnlMy2ME543d7LSg38hN552nk6WA21Qh+0h8S/EQN5DlLfWw= MIME-Version: 1.0 X-Received: by 10.157.19.36 with SMTP id f33mr2201716ote.36.1517966001660; Tue, 06 Feb 2018 17:13:21 -0800 (PST) Date: Tue, 6 Feb 2018 17:12:39 -0800 In-Reply-To: <20180207011312.189834-1-bmwill@google.com> Message-Id: <20180207011312.189834-3-bmwill@google.com> References: <20180125235838.138135-1-bmwill@google.com> <20180207011312.189834-1-bmwill@google.com> X-Mailer: git-send-email 2.16.0.rc1.238.g530d649a79-goog Subject: [PATCH v3 02/35] pkt-line: introduce struct packet_reader From: Brandon Williams To: git@vger.kernel.org Cc: sbeller@google.com, peff@peff.net, gitster@pobox.com, jrnieder@gmail.com, stolee@gmail.com, git@jeffhostetler.com, pclouds@gmail.com, Brandon Williams Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Sometimes it is advantageous to be able to peek the next packet line without consuming it (e.g. to be able to determine the protocol version a server is speaking). In order to do that introduce 'struct packet_reader' which is an abstraction around the normal packet reading logic. This enables a caller to be able to peek a single line at a time using 'packet_reader_peek()' and having a caller consume a line by calling 'packet_reader_read()'. Signed-off-by: Brandon Williams --- pkt-line.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ pkt-line.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/pkt-line.c b/pkt-line.c index af0d2430f..4fc9ad4b0 100644 --- a/pkt-line.c +++ b/pkt-line.c @@ -406,3 +406,62 @@ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out) } return sb_out->len - orig_len; } + +/* Packet Reader Functions */ +void packet_reader_init(struct packet_reader *reader, int fd, + char *src_buffer, size_t src_len, + int options) +{ + memset(reader, 0, sizeof(*reader)); + + reader->fd = fd; + reader->src_buffer = src_buffer; + reader->src_len = src_len; + reader->buffer = packet_buffer; + reader->buffer_size = sizeof(packet_buffer); + reader->options = options; +} + +enum packet_read_status packet_reader_read(struct packet_reader *reader) +{ + if (reader->line_peeked) { + reader->line_peeked = 0; + return reader->status; + } + + reader->status = packet_read_with_status(reader->fd, + &reader->src_buffer, + &reader->src_len, + reader->buffer, + reader->buffer_size, + &reader->pktlen, + reader->options); + + switch (reader->status) { + case PACKET_READ_EOF: + reader->pktlen = -1; + reader->line = NULL; + break; + case PACKET_READ_NORMAL: + reader->line = reader->buffer; + break; + case PACKET_READ_FLUSH: + reader->pktlen = 0; + reader->line = NULL; + break; + } + + return reader->status; +} + +enum packet_read_status packet_reader_peek(struct packet_reader *reader) +{ + /* Only allow peeking a single line */ + if (reader->line_peeked) + return reader->status; + + /* Peek a line by reading it and setting peeked flag */ + packet_reader_read(reader); + reader->line_peeked = 1; + return reader->status; +} diff --git a/pkt-line.h b/pkt-line.h index 06c468927..7d9f0e537 100644 --- a/pkt-line.h +++ b/pkt-line.h @@ -111,6 +111,64 @@ char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size); */ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out); +struct packet_reader { + /* source file descriptor */ + int fd; + + /* source buffer and its size */ + char *src_buffer; + size_t src_len; + + /* buffer that pkt-lines are read into and its size */ + char *buffer; + unsigned buffer_size; + + /* options to be used during reads */ + int options; + + /* status of the last read */ + enum packet_read_status status; + + /* length of data read during the last read */ + int pktlen; + + /* the last line read */ + const char *line; + + /* indicates if a line has been peeked */ + int line_peeked; +}; + +/* + * Initialize a 'struct packet_reader' object which is an + * abstraction around the 'packet_read_with_status()' function. + */ +extern void packet_reader_init(struct packet_reader *reader, int fd, + char *src_buffer, size_t src_len, + int options); + +/* + * Perform a packet read and return the status of the read. + * The values of 'pktlen' and 'line' are updated based on the status of the + * read as follows: + * + * PACKET_READ_ERROR: 'pktlen' is set to '-1' and 'line' is set to NULL + * PACKET_READ_NORMAL: 'pktlen' is set to the number of bytes read + * 'line' is set to point at the read line + * PACKET_READ_FLUSH: 'pktlen' is set to '0' and 'line' is set to NULL + */ +extern enum packet_read_status packet_reader_read(struct packet_reader *reader); + +/* + * Peek the next packet line without consuming it and return the status. + * The next call to 'packet_reader_read()' will perform a read of the same line + * that was peeked, consuming the line. + * + * Peeking multiple times without calling 'packet_reader_read()' will return + * the same result. + */ +extern enum packet_read_status packet_reader_peek(struct packet_reader *reader); + #define DEFAULT_PACKET_MAX 1000 #define LARGE_PACKET_MAX 65520 #define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4) -- 2.16.0.rc1.238.g530d649a79-goog